namespace IPDF
{
-/** Greatest Common Divisor - Euclid's algorithm **/
-
+/* Recursive version of GCD
template <class T>
T gcd(const T & a, const T & b)
{
if (a > b) return gcd(a-b,b);
return gcd(a, b-a);
}
+*/
-/*
+/** Greatest Common Divisor of p and q **/
template <class T>
T gcd(const T & p, const T & q)
{
- Debug("p/q = %
T g(1);
T big(p);
T small(q);
}
return small;
}
-*/
+
template <class T = int64_t>
struct Rational
{
/** Construct from a double.**/
- Rational(double d = 0) : P(d*1e3), Q(1e3) // Possibly the worst thing ever...
+ Rational(double d=0) : P(d*1e6), Q(1e6) // Possibly the worst thing ever...
{
Simplify();
- //CheckAccuracy(d, "Construct from double");
+ CheckAccuracy(d, "Construct from double");
}
Rational(const T & _P, const T & _Q) : P(_P), Q(_Q)
P = (P < 0) ? -P : P;
Q = -Q;
}
-
+ if (P == 0)
+ {
+ Q = 1;
+ return;
+ }
T g = gcd(llabs(P),llabs(Q));
P /= g;
Q /= g;
bool operator>=(const Rational & r) const {return *this == r || *this > r;}
bool operator!=(const Rational & r) const {return !(*this == r);}
-
-
- /*
Rational operator+(const Rational & r) const
{
Rational result = (r.P == 0) ? Rational(P,Q) : Rational(P*r.Q + r.P*Q, Q*r.Q);
result.CheckAccuracy(ToDouble() - r.ToDouble(),"-");
return result;
}
- */
Rational operator*(const Rational & r) const
{
Rational result(P * r.P, Q * r.Q);
}
Rational operator/(const Rational & r) const
{
- Rational result = (r.P == 0) ? Rational(P,Q) : Rational(P*r.Q + r.P*Q, Q*r.Q);
- if (!result.CheckAccuracy(ToDouble() / r.ToDouble(),"*"))
+ Rational result(P * r.Q, Q*r.P);
+ if (!result.CheckAccuracy(ToDouble() / r.ToDouble(),"/"))
{
Debug("This is %s (%f) and r is %s (%f)", Str().c_str(), ToDouble(), r.Str().c_str(), r.ToDouble());
}
return result;
}
- Rational operator+(const Rational & r) const {return Rational(ToDouble()+r.ToDouble());}
- Rational operator-(const Rational & r) const {return Rational(ToDouble()-r.ToDouble());}
+ /** To cheat, use these **/
+ //Rational operator+(const Rational & r) const {return Rational(ToDouble()+r.ToDouble());}
+ //Rational operator-(const Rational & r) const {return Rational(ToDouble()-r.ToDouble());}
//Rational operator*(const Rational & r) const {return Rational(ToDouble()*r.ToDouble());}
//Rational operator/(const Rational & r) const {return Rational(ToDouble()/r.ToDouble());}
Rational & operator/=(const Rational & r) {this->operator=(*this/r); return *this;}
double ToDouble() const {return (double)(P) / (double)(Q);}
- bool CheckAccuracy(double d, const char * msg, double threshold = 1e-6) const
+ bool CheckAccuracy(double d, const char * msg, double threshold = 1e-3) const
{
double result = fabs(ToDouble() - d) / d;
if (result > threshold)